The invention relates to a cutting device for products, in particular for cutting foodstuffs, which consists of a blade driven by a drive shaft so as to rotate and a rotor driven by a further drive shaft. The blade orbits the further drive shaft of the rotor in a planetary path-like manner.
Cutting devices of this type are used to cut up foodstuffs, such as lengths of sausages prepared on an industrial scale (length up to 160 cm), at high speed. For this purpose, the sausage is supplied to a rotating blade in the direction of the axis of rotation of the blade by a conveying means, for example a moving support face of a transport claw acting at the end or conveyor belts acting laterally/from above and is cut up into individual slices during this supply process by the rotating blade. Circular blades are preferably used in the above-mentioned cutting devices. The circular blades do not have any unbalanced mass with respect to their drive shaft, whereby the mounting of the blade rotating at high speed is greatly facilitated. The blade must be moved such that it periodically exposes the cutting region for the subsequent supply of the foodstuff article to be cut up. For this purpose the blade is arranged on the rotor with its axis of rotation such that, in addition to its own rotation, it rotates on a planetary path round the further drive shaft of the rotor.
In a cutting device of this type the rotating rotor is driven by a drive belt which is located, for example, round the outside of the rotor. In FIG. 1, which shows a cutting device according to the state of the art, an example of a drive of this type by means of drive belts is indicated by the arrow designated by the reference numeral 6. The blade 1 rotating in the opposite direction is driven by a drive shaft 3 and a driven shaft 4, which are connected to one another by a gearing, at the back of the rotor 2. The drive belt, which, for example, can be a toothed belt, is housed together with the rotor 2 inside a housing 7 in a drive region 8 of the cutting device. This housing 7 is separated from the product at the blade-side, i.e. at the transition of the drive region into a product region 9, by a cover 10, as shown in FIG. 1, wherein such a cover 10 must of course have a recess of the size of the cross-section of the rotor 2. As the rotor 2 is in a constantly rotating state, a seal at the gap 11 between the cover and the rotor and toward the product region is only, if at all, inadequately possible. Therefore, the cover 10 has only a limited separating function between the product region 9 and the drive region 8 in which the drive belt and the rotor 2 are located. An accumulation of product scraps, which fall off during the cutting process, inside the drive housing and therefore inside the drive region is therefore unavoidable.
Owing to gravity, such product scraps, such as cutting residue, together with lubricant residue, such as grease from the toothed wheel belts, accumulate in the lower region of the drive housing 7. Dirt particles and water from the high-pressure cleaning process which must be performed at regular intervals on the cutting device in the product region are generally added to this mixture. Cleaning using high-pressure would be a suitable and desirable means for rapid cleaning of the soiled drive region. However, for this purpose it is necessary to dismantle the cover 10 and to make modifications to the drive engineering, in order to provide an open access to the drive region for the cleaning equipment. The disadvantage of such a cleaning process is not only the large amount of time required, but also the complicated handling of the cutting device before the actual cleaning process can be started.
Owing to the portion of the cover 10 located at the bottom and the lower wall of the drive housing adjacent thereto the spacing between the rotor 2 and the product is limited to a necessary maximum value, resulting in a disadvantageous limited maximum value of product cross-section which can be cut, or in larger blades which have to be driven with more energy and which owing to the higher angular momentum lead to larger and therefore also more expensive bearings.
The object of the invention is therefore to provide a cutting device, in particular for cutting foodstuffs, which has an improved seal with respect to the product to be cut and, in terms of its construction, is easier to clean and is therefore more hygienic.
This object is achieved according to the characterising part of claim 1, for owing to the arrangement of the one drive shaft in the other drive shaft designed as a hollow shaft it is possible to omit the drive belt which is located round the housing of the rotor and instead to supply the entire drive of the cutting device at the back, i.e. the side remote from the product, of the cutting device. This shaft-in-shaft system allows not only the rotating rotor and blade rotating in a planetary path-like manner to be driven simultaneously in a simple way, but also an optimal seal at the entry point of the shaft-in-shaft system into the rotor and therefore a hygienically operable rotor inside the product region of the cutting device.
Owing to the use of the shaft-in-shaft system it is no longer necessary to drive the rotor via a separate toothed belt at the outside of the rotor housing and to drive the blade via a gearing which connects the drive shaft and the driven shaft of the blade and is arranged outside the rotor housing. This results in a simplified form of the rotor and therefore of the entire cutting device produced, which is simpler and also more compact.
In addition, the shaft-in-shaft system results in the decisive advantage of a rotor, including blade, which is freely suspended and closed and sealed in the product region and is separated from the drive region by a partition wall, so mixing of lubricants and product scraps is no longer possible. The cutting device is therefore more hygienic. If a cleaning process is started the freely suspended closed rotor housing, together with the remaining product region, can be cleaned in a straightforward manner by means of a high-pressure cleaner regardless of the drive region and without further preparation measures.
It is advantageous in this case for the drive sources to be separated from the rotor and the blade by a partition wall. The drive sources are connected in the conveying direction of the foodstuff article in the region remote from the blade. As a result, an arrangement which is compact and also makes optimum use of space is selected.
It is provided in a preferred development of the invention that a rotor housing directly faces the product. Owing to this arrangement the additional housing (designated as housing 7 in FIG. 1) known in the state of the art can be dispensed with. This results in an effective cutting edge being arranged closer to the product support with a product type which appears to be identical. Cutting blades can be constructed so as to be smaller with a lower angular momentum. As a result, an associated reduction in construction costs for the mounting thereof can be obtained.
In addition, owing to the arrangement of the rotor in the product region, it is possible to advance the rotor toward the product upper edge without limitation, so product cross-sections of greater dimension can now be cut.
Owing to the arrangement of the connecting devices between drive shaft and driven shaft of the blade inside the closed rotor regular maintenance of this connecting device with lubrication and cleaning thereof is largely unnecessary.
The balance weights required owing to the planetary path-like movement of the blade can now similarly be housed completely within the closed rotor housing. This results in a simplified and more compact external form of the cutting device.
It is of particular advantage in this case that the arrangement of blade counterweights, such as blade counterweight M4 in FIG. 1, can be dispensed with. This impeded operation as it had to be attached in the front product region and interfered during the cutting process in such a way that it struck away the uppermost slice of the cut product slice stack. As a result of the development according to the invention, the blade weights can be housed in the rotor housing so the external blade weight and the disadvantages associated therewith no longer exists.
In a preferred development of the invention it is provided that the drive shaft guided in the hollow shaft drives either the cutting blade or the rotor. The hollow shaft then drives either of the other of the rotor or the cutting blade. In each case it is possible to establish control of the various elements by the two shafts guided one inside the other in accordance with requirements.
In this case it is provided that the drive sources of the hollow shaft or of the drive shaft located therein are either independent electric motors or else that the rotation is derived from a common drive motor, for example by means of gearing. A further drive can be dispensed with as a result of such a development, in particular as, owing to the parallel arrangement of the two shafts, a relatively space-saving, compact arrangement is possible anyway. A separate drive shaft in the form of a gearing is optionally provided as a result of which the torque is derived from the drive motor. It is possible in this case to arrange the gearing in such a way that the shafts run in the same or opposing direction(s). This can, of course, also be achieved by two electric motors appropriately connected in opposing directions.